In the past four years, average base pay at the USPS has dropped by 4%. While that might not be great news for the workers themselves, it seems like it should be a good thing for the struggling postal service, and a big help in making ends meet.

But those lower wages are coming at a high price, according to the ever-informative D. Eadward Tree.

“The U.S. Postal Service’s shift to a lower-paid workforce comes with a steep price. By the agency’s own admission, the hiring of more non-career employees has led to lower productivity, worse service, higher injury and turnover rates, and increased investment in new training programs,” Tree writes in a blog post on USPS new hires last week.

“USPS has historically been staffed by long-serving employees, but currently 103,000-plus employees — one of every six active postal workers — has been with the agency less than a year. That’s triple the newbie rate of just four years ago,” he continues.

Part of the blame rests with the new labor contracts that take good care of current union members at the expense of new hires, the so-called “eat your young” contracts. New hires are often classified as “non-career,” with less experience than typical. Training costs skyrocket, injuries rise, performance suffers and service goals go unmet. In short, the USPS falls further and further behind.

The USPS has both regulatory pressure and union muscle pushing in on them, and finding an equitable middle has got to be a challenge. Still, they have to take some measure of responsibility for managing their own house. This ongoing saga of bad decision-making and poor execution is putting the direct marketing industry in a dicey position.